Simple Closed Loop System for Direct Harvest and Transfer for High Volume Fat Grafting

ABSTRACT

This invention proposes the construction of a simple closed loop system for continuous flow harvesting, collection, syphoning, and grafting of large volumes of fat. (See FIG.  1 —a schematic of the overall setup). This invention uniquely bypasses the standard cumbersome and time-consuming process, that mainly being the need to first transfer fat into individual syringes prior to grafting into the patient. This is traditionally done with unmeasured, manual pressures as generated by a simple plunger syringe. It can be messy and sloppy, with loss of fat. In contrast, this innovative concept presented here simplifies the whole process into a closed loop, from the donor harvest site, and then back to the patient. The concept is modular, drawing on commonly used, interchangeable parts and pumps present and available in most basic community hospital operating rooms. The major benefit is a significant reduction in time to transfer. However there is also a simplification of the process with less air exposure time, consistent controlled limit on flow pressures, and a simple on off control that can be held in one hand. The system is adaptable to standard liposuction and introduction cannulas through standard liposuction tubing and a luer lock connection. Collection canisters are also interchangeable.

BRIEF DESCRIPTION OF FIGURES & DRAWINGS

FIG. 1: Sketch of Invention “A Simple Closed Loop System for DirectHarvest and Transfer for High Volume Fat Grafting”. This Figure is alabeled outline sketched by myself, showing the separate components forthe system and how they are connected together with respect to the flowand direction of the fat harvesting.

FIG. 2: Photograph of a sample set up in the operating room, with allthe components connected to build the Loop System. There is alipo-aspirate harvesting cannulas (large at bottom) and smaller fatintroduction cannulas directly attached (center). The collectioncanister is seen top center, and pump component is on the upper left.

FIG. 3: Sample of simple clamp used to control flow of transferred fat.The operators hand used to introduce the fat can easily operate theclamp.

FIG. 4: Photo of a pulsatile pump that is loaded and charged with fat intubing for transfer.

BACKGROUND

Fat grafting as an adjunct for contour modulation in breastreconstruction has become fairly commonplace¹⁻³ since The AmericanSociety of Plastic Surgeons lifted a ban on fat grafting to the breastin 2009. Optimal methods and techniques of transfer and fat handling hasbecome a hot area of research and technological development. Manytechniques involve the transfer of fat back into the breast via a handheld 60 cc syringe powered by manual plunger. Recently, Khouri^(4,5) haschampioned ‘megavolume fat transfer’ for breast reconstruction,designating mega as >300 cc per breast. Extrapolating this process totwo breasts would necessitate at least ten 60 cc syringes. Transferringfat into syringes and refitting the plungers is tedious. Small amountsof fat may be spilt or lost with the filling each syringe. Multiplyingby ten syringes adds up to wasted viable tissue. Manually forcing theplunger after already performing manual or assisted liposuction istiresome on the hands. A technique to streamline this process, bypassingthe syringe step and supplying a gentle controlled pressure for infusionsaves precious operating time and anesthesia time for the patient,allows controlled flow and minimizes the time the graft is out of thepatient. It also relieves significant wear and tear on a surgeon'shands.

METHOD See FIG. 3: Photograph of all 3 Components Connected as OneSystem—Harvesting, Processing and Transfer 1. Fat Harvest:

This may be done through a variety of techniques but basically anystandard or preferred liposuction cannulas, connecting the liposuctiontubing to a canister reservoir with an outflow luer lock, such as theJAC Cell®, Revolve®, or other sterile collection system.

2. Processing:

This may be done through the surgeons preferred technique, depending onthe canister system used. If the JAC cell is used than the aqueous layeris allowed to decant and is first syphoned off through the luer lockconnection.

3. Fat Transfer:

A pulsatile pump, with upper pressures limited to 150-350 mm HG, is thenconnected to the outflow valve of the fat collection canister. Forexample the Arthrex® Pump with slightly wider bore tubing works wellwithout clogging, but other tubing as well can be adapted. The two endsof the tubing remain on the operative field with sterility preserved.The tubing can be directly connected to most standard fat transfercannulas. A simple clamp (see FIG. 3) on the tubing allows the operatorto control the flow of the fat and introduction all with one hand, whilethe other hand is free to palpate tissue turgor, contour and position ofthe recipient bed or breast. (See FIG. 4 example of fat loaded andflowing through pump)

REFERENCES

-   1. Spear S L, Wilson H B, Lockwood M D. Fat injection to correct    contour deformities in the reconstructed breast. Plast Reconstr    Surg. 2005; 116:1300-1305.-   2. Coleman S R, Saboeiro A P. Fat grafting to the breast revisited:    Safety and efficacy. Plast Reconstr Surg. 2007; 119:775-785;-   3. Delay E, Garson S, Tousson G, Sinna R. Fat injection to the    breast: Technique, results, and indications based on 880 procedures    over 10 years. Aesthet Surg J. 2009; 29:360-376.-   4. Khouri R K, Rigotti G, Cardoso E, Khouri R K Jr, Biggs T M.    Megavolume autologous fat transfer: Part I: Theory and Principles.    Plast Reconstr Surg. 2014; 133:550-557.-   5. Khouri, Roger K. M.D.; Rigotti, Gino M.D.; Cardoso, Eufemiano    M.D.; Khouri, Roger K. Jr. B. S.; Biggs, Thomas M. M.D. Megavolume    Autologous Fat Transfer: Part II. Practice and Techniques. Plast    Reconstr Surg. 2014; 133:1369-1377.

1. A method of harvesting and transferring large volumes of fat forgrafting in a sterile closed circuit system, wherein the method: a)Saves operating and anesthesia times b) Limits spillage and waste ofgraft tissue c) Decreases manual force needed d) Decreases strain andfatigue on the surgeon's hands, e) Limits air exposure of graftmaterial. f) Moreover the system can be built using multipleinterchangeable components already in use in various aspects of fatgrafting and fluid transfer, but their utilization together as a systemprovides a time and facility benefit greater than the sum of the partsalone.